With the rapid development of computer technologies, screen sharing applications, which were once limited to enterprise applications such as remote desktop control of office computers, have now become available to common users for entertainment and communications, for example. These screen sharing applications usually involve at least two computing devices which necessarily communicate screen data over a data network between the two computing devices. In order to provide real-time interactive screen sharing experience and reduce the amount of data sent over the network, the screen data is usually encoded and compressed prior to sending. Conventional hybrid video coding schemes, such as H.264 and HEVC (High Efficiency Video Coding), which are based on transform domain quantization and entropy coding, have been widely used for this purpose. These hybrid video coding schemes, however, are normally efficient for encoding nature videos, but fail to provide efficient coding and compression results for other types of content such as text content or other high-gradient content which normally constitute a large portion of the screen data. Therefore, unless a coding scheme that can adaptively and efficiently perform coding and compression for a variety of types of content is developed, these screen sharing applications, though implementable, may fail to achieve a screen sharing performance that is satisfactory to most users.